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A fun, free platform for learning modern cryptography

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Learn By Doing

Learn about modern cryptography by solving a series of interactive puzzles and challenges. Get to know the ciphers and protocols that secure the digital world by breaking them.

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Level Up

Earn points by solving challenges. Finish categories to earn trophies and gain levels to track your progress. Can you reach the top of the scoreboard?

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Fresh Challenges

We are constantly creating new challenges to keep your crypto knowledge up to date. Expect exciting brainteasers and whole new categories as the site continues to grow.

New Challenges
RSA or HMAC? Part 2 Crypto on the Web 100
Roll your Own Mathematics 125
Dancing Queen Symmetric Ciphers 120
SSH Keys General 35
LFSR Destroyer Misc 250
Weekly Top Users
#1 grhkm 2645
#2 khasreto 1785
#3 eternalcirno 1785
#4 mathphilia_271 1715
#5 oauy9wjz4eyua6aw 1690
Recent Solves
RSA Backdoor Viability randomdude999
Base64 Edu_ard
ASCII pai9maker
Great Snakes Fab1an
Transparency trnam11
Recent Solutions
Jeff's LFSR jd 0
Null or Never pwang00 0
Point Addition deNableD 0
Chinese Remainder Theorem B0b 0
Modular Square Root B0b 0

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